I tested this software after seeing its reviews in photography magazines - The professionals were acting like the was the best software since Adobe Photoshop so I had to look into it... First of all, you must have at least 3 GB of ram or it will likely freeze on you. My PC with 1 GB wouldn't process the images - the PC with 3 GB would (similar processors). I found that it was a great too for reducing noise, but not much, if any, better than Photoshop. If they do not have your camera/lens combination listed as being supported, the software is completely useless. I'd invest in something that's still going to work for you should you ever decide to change camera/lens.
All in all, I used it several times during trial period to test with 350d/sigma 8mm combination and didn't find it useful enough to buy - I get better results with the new canon 40D and sigma anyway now (combination not supported by this software yet).